Efficient Antigen Presentation to Cytotoxic T Lymphocytes by Cells Transduced with a Retroviral Vector Expressing the HIV-1 Nef Protein

In the classic model of antigen processing and presentation, viral antigens must be synthesized within the cytoplasm of infected cells to be processed and presented to CD8⁺, MHC class I-restricted cytotoxic T lymphocytes (CTLs). We have examined the utility of a retroviral vector (pNeoNef) expressing the human immunodeficiency virus type (HIV-1)_Lai Nef protein for the development of target cells to study HIV-specific CTLs. Autologous Epstein-Barr-transformed B cell lines (EBV-B cells) transduced with pNeoNef were efficiently lysed by CTL lines from donors capable of lysing EBV-B cells infected with a recombinant vaccinia virus (rVV) expressing Nef. Also, the transduced cells were efficient stimulator cells for the generation of Nef-specific CTL lines. The CTL lines thus generated recognized the same epitopes as CTL lines from the same donor generated by nonspecific stimulation. The use of similar cell lines transduced with retroviral vectors expressing HIV proteins may be useful in the study of CTLs in HIV-infected donors and in the study of the ability of candidate vaccines, including rVV, to induce HIV-specific CTLs. As antigen-presenting cells, the cell lines may be useful in the generation of antigen-specific CTL lines.